Device for measuring,sewing and cutting endless bands



June 10, 1969 s. v. TH'OMSEN 3,443,707

DEVICE FOR MEASURING, SEWING AND CUTTING ENDLESS BANDS Filed Dec. 11. 1967 Sheet of 2 FIG].

INVENTOR GERT VILNER THOMSEN ATTORNE June '10, 1969 I v, THOMISEN 3,448,707

I DEVICE FOR MEASURING, SEWING AND CUTTING ENDLESSYBANDS Sheet of 2 Filed Dec. 11. 1967 INVENTOR United States Patent 3,448,707 DEVICE FOR MEASURING, SEWING AND CUTTING ENDLESS BANDS Gert Vilner Thomsen, Viborg, Denmark, assignor to K/ S Asani, Viborg, Denmark, a partnership of Denmark Filed Dec. 11, 1967, Ser. No. 690,051 Int. Cl. Db 23/00, 37/04 U.S. Cl. 112-2 11 Claims ABSTRACT OF THE DISCLOSURE A sewing machine attachment for automatic production of endless bands in which a disc carries bars for winding band material into a continuous loop when the disc is rotated. The disc is axially movable on a drive shaft from a position in which it is rotatably coupled to the shaft for winding the band material, and a second position in which it is uncoupled from said shaft and in cooperative engagement with the sewing machine for sewing of the band loop ends together. A cam guide cooperates with a notch in the disc for halting rotation of the uncoupled disc and for guiding the band loop accurately toward the sewing machine.

The present invention relates to an attachment or device, designed to be mounted on a sewing machine which is capable of sewing together the ends of a predetermined length of tape to form an endless band. The device is so constructed that the measuring of the length of the band from a supply magazine, and the subsequent sewing together of the band ends to form one endless band, and the severing of the endless band from the fed band material may be accomplished automatically. The device is especially intended for the manufacture of endless elastic bands used in underwear.

Prior to the present invention, the usual procedure for producing such endless bands has been the measure the length of the band, cut the band into the desired lengths, manually stack the bands on top of each other with their ends in alignment and finally to put these aligned ends under the presser foot of the sewing machine for sewing them together.

Accordingly, among the principal objects of the present invention is to provide a device of the character described which will allow the various steps of the above described operation to be performed automatically, with a significant reduction in the operation time.

Another object of the present invention is to provide a device of the character described in which the size of the band loops to be formed can be selectively varied without interfering with the automatic operation of the device.

A further object of the present invention is to provide a device of the character described which will allow severance of the formed and sewn endless bands from the band material continuously fed from a magazine supply.

In accordance with the invention herein there is provided an attachment which may be secured to a sewing machine frame and includes an axially movable disc mounted on a shaft, the axis of rotation of the disc and shaft being parallel to the longitudinal axis of the sewing machine. The surface of the disc facing the feeding end of the sewing machine is provided with a plurality of perpendicular bars, which serve as winding units for a band which is fed continuously from a supply magazine. The disc may be detachably engaged to the shaft by well known coupling means so that when coupling has been accomplished the disc will rotate with the shaft. Means are provided to stop the rotation of the disc upon 3,448,707 Patented June 10, 1969 "ice the completion of one revolution, simultaneously uncoupling the disc from the shaft and moving it toward the sewing machine. The forward movement is stopped when the parts of the band to be sewn together are properly located within the feeding end of the sewing machine. The sewing operation is completed and the endless band which has been formed is severed from the supply magazine band. The completed endless band is removed, and the operation may then be repeated.

Additional objects and advantages of the present invention will become apparent from a consideration of the following detailed description when taken in conjunction with the accompanying drawings, in which:

FIG. 1 is a fragmentary top plan view of a device made in accordance with the present invention, showing part of the sewing machine upon which it is mounted, with the band winding disc of the device being shown in solid lines as coupled to the shaft upon which it is mounted, and its forward portion shown in broken line to indicate its uncoupled position for sewing;

FIG. 2 is a section taken along line IIII of FIG. 1;

FIG. 3 is an enlarged section taken along line IIIIII of FIG. 1, and showing the position of the endless band with the sewing machine during the sewing operation;

FIG. 4 is a sectional view similar to FIG. 3 after severance and removal of the endless band from the device; and

FIG. 5 is an enlarged section taken along the line VV of FIG. 2.

Referring in detail to the drawings, and in particular to FIG. 1 there is shown a portion of a sewing machine, namely the lowerforward-pointing arm- 1 providing the bed upon which the sewing operation takes place, and the presser foot 2 and needle 3.

Parallel to the longitudinal axis of the sewing machine and forwardly of arm 1, a shaft 4 is pivotally suspended from a frame 5 which may be made integrally with the frame of the sewing machine. Shaft 4 is driven by a separate motor (not shown), which is operated to rotate the shaft as long as the production of bands is in progress. Mounted on the end portion of the shaft 4 facing the sewing machine, as shown in FIG. 1, is a relatively large circular disc 6, axially displaceable along the shaft between a flange 7 affixed to the shaft and a disc 8 clamped onto the end of the shaft. Movement of the disc 6 is effected by means of a double-armed lever 9, pivoted 'at 9a to frame 5. The front arm of lever 9 carries a pivoted block 9b which rides within an annular slot 6b at the end of an elongated hub extension 6a of disc 6.

The lever 9 may be moved by means of a pitman unit 10, connected to the rear arm of said lever. The lever 9 is shown in its starting position in FIG. 1. When the rear arm of the lever 9 is drawn down by the pitman unit '10 to move the disc 6 forwardly along the shaft 4, spring 11, which is secured to said rear arm, is tensioned. Upon release of the force of the pitman unit 10, the spring 11 will automatically pull the lever back to its starting position.

Disc 6 is provided with a plurality of fixed bars 12, 12a which are parallel to the axis of rotation of the disc and which extend'outwardly towards the feeding end of the sewing machine. These bars 12, 12a serve as winding bars for the predetermined length of band coming from the supply magazine, which is to form the endless hand. To bar 1211 is secured one end of a strip 13 of sheet spring material which extends longitudinally along bar 12a. The end of the band 14 from the supply magazine is inserted between this spring strip 13 and the underlying portion of bar 12a and held firmly by the spring strip.

The disc 6 may be rotatably coupled to and uncoupled from the driving shaft 4. For this purpose, the elongated disc hub extension 6a has a pin or dowel projecting outwardly therefrom and sized to fit into a corresponding opening 15:: in the flange 7 which is attached to the driving shaft, when the disc 6 is in the rearward position indicated by solid lines in FIG. 1.

The uncoupling of the disc 6 from shaft 4 is accomplished by means of lever arm 9. It is necessary that the disengagement take place only after the disc has completed one revolution and only when winding bar 12a is positioned in front of the arm 1 and the sewing units of the sewing machine. The disc 6 has a notch 17 (FIG. 2) either in a part 16 projecting from its periphery or directly in its periphery at a specified point. The notch 17 is sized and shaped toreceive therein a cam guide 18 which is secured to frame 5. As shown in FIG. 5, the lower edge of notch 17 forms an included plane 17a sloping downwardly towards the sewing machine. The end of cam guide 18 facing the disc 6 is in the shape of a wedge 19 whose upper surface is at right angles to the plane surface of the disc. The other end of cam guide 18 is in the form of a chisel-shaped wedge 20*. During rotation of the disc 6, the projecting portion 16 moves to a position opposite wedge 19 of cam 18, and as the pitman unit 10 pivots lever arm 9, the disc will move forward until it engages wedge 19. As the disc 6 is gradually rotated further the inclined surface 17a of notch 17 will cause the disc to move across the cam 18 until the dowel 15 moves out of opening 15a and the disc hub extension 6a disengages from the flange 7 of the driving shaft 4. The disc 6 will then move forwardly without hindrance until stopped by disc 8 mounted on the end of the shaft 4. In FIG. 1, the dotted lines indicate the position of the bars 12 when the disc has moved to its forwardmost position.

As shown in FIG. 2, winding bar 12a is mounted near the periphery of disc 6. At a specified distance from the winding bar 12a, a second winding bar 12b is similarly secured. The spacing between the bars 12a and 12b is such that as the disc 6 is moved toward the sewing machine arm 1, the bars 12a and 1212 will slide along either side of the presser foot 2, as indicated in broken line in FIG. 1. In a similar manner there are two additional stationary winding bars 12 symmetrically arranged, one on either side of the bars 12a and 12b. The aforementioned four bars are so located on disc 6 and are so arranged relative to each other that the band 14 carried by these bars may be moved above and across sewing machine arm 1 without touching it, as indicated in FIG. 1. The other winding bars 12 may be selectively placed at varying distances from the axis of rotation of the disc 6, their location and numbers being dependent upon the specific circumference of the band loop required. As shown in FIG. 2, the disc has a plurality of rows of radially positioned holes 21 in which the winding bars can be set, and by moving the winding bars to different radial distances from the axis of rotation of the disc and by placing a larger or smaller number of bars than shown in the drawing, the size of the band loop may be varied. It will be apparent that each row of holes 21 may be replaced by a radial groove to provide a greater degree of adjustability.

The winding unit, consisting of disc 6 and its winding bars 12, 12a and 12b, cooperates with a feeding unit 22 from which is fed the band 14 prior to its positioning around the bars. The feeding unit is situated on a carriage (not shown) which moves axially with the winding unit. Above the feeding unit 22 is located a leaf spring 23 which presses the band firmly against the upper sliding surface of the feeding unit. The band 14 may be fed from a magazine supply, such as a reel upon which a large production quantity of the band may be wound.

The feeding unit 22 initiates the band-forming cycle by inserting the free end of the band material 14 upon bar 12a so that the band end is gripped thereon in a manner to be described in detail. The disc is now rotated by shaft 4 through one complete revolution, forming a circular band around bars 12. At the end of the disc rotation, the notch 17 is aligned with the guide cam 18, and the disc is moved forward on shaft 4, so that it uncouples from said shaft 4 and the guide cam 18 is received in notch 17 to prevent further rotation of disc 6. In this position, the band ends, located between bars 12a and 12b, are aligned with the needle 3 and presser foot 2. As the disc 6 is moved further forwardly by pitman unit 10, the band 4 is brought beneath the needle 3, in the position shown in broken line in FIG. 1, so that the band ends can be sewn together. In this operative sewing position, the notch 17 of disc 6 has moved past and is free of guide cam 18, so that disc 6 is freely turnable on shaft 4, and can follow the sewing movements of the sewing machine.

The device also includes a cut-off knife 24 which is pivotally attached to the upper surface of presser foot 2 of the sewing machine. When swung across the edge surface of the presser foot 2, the knife 24 cuts the band 14.

The device may be integrally formed with or secured to the frame of a sewing machine. In operation, a supply of band material 14 of the desired width and composition is wound on a reel or the like within the magazine supply and is fed through feeding unit 22, between spring strip 13 and winding bar 12a, being held firmly in place by the spring strip. Additional winding bars 12 are placed within the holes 21 at desired locations to provide an endless band of the desired circumference. The sewing machine is placed in operational condition, and the motor powering the driving shaft 4 is energized. Dowel 15 is inserted within opening 15a and the driving shaft 4 causes the disc 6 to rotate in the direction indicated by arrow A in FIGS. 2 and 4. The rotational movement of disc 6 and the bar 12a carrying the end of the band material, causes the band 14 to engage the various winding bars, forming a loop of predetermined length, as shown in FIG. 2. After the disc has made one complete revolution of 360, its rotating movement is brought to a halt, in a manner to be presently described.

Shortly before notch 17 of the disc 6 has reached a position where the notch is in line with the guide cam 18 of frame 5, the release operation of the disc commences. The pitman unit 10 causes lever arm 9 to turn, moving the still rotating disc until it rests against wedge 19 of the cam 18, and after a further short rotational movement, the disc 6 moves axially along the shaft 4 until its coupling dowel 15 moves free of opening 15a, releasing the disc 6 from its connection with flange 7. The disc then moves further forwardly along shaft 4 until it rests against stop disc 8. In this position the fixed winding bar 12a has slid along one side of the presser foot 2 whereas the other fixed winding bar 121) has come to a position along the other side of the presser foot. At this point cam 18 passes into notch 17 and the disc is stopped as shown in FIG. 2. The broken line representation of FIG. 1 shows the :position of the winding units and the loops in relation to the presser foot 2 of the sewing machine after winding disc 6 is in abutment with disc 8 on shaft 4, and in this position the band portion extending between the bars 12a and 1211, that is to say the front end of the band 14 and the rear end to which it is to be joined, is immediately beneath needle 3 of the sewing machine.

Presser foot 2 of the sewing machine is then lowered to the position shown in FIG. 3 and the sewing operation is commenced. During the sewing the presser foot 2 reciprocates transversley as indicated by arrow B in FIG. 3, and during these movements the uncoupled Winding disc 6 makes similar motions. This free movement of disc 6 is possible because the length of guide cam 18 is such that the winding disc 6 in its displaced outer position is completely released from the guide cam. When the sewing operation has been completed, the sewing machine stops and the horizontal knife 24 is pivoted on presser foot 2, sweeping under the feeding unit 22 to cut the band along the upper edge of the presser foot, this edge being sharpened so it and the knife coact in the manner of scissor blades.

After the trimming of the endless band has been completed, and the sewn-together loop has been severed from the fed band material, the pitman unit is released and spring 11 causes the lever 9 to move the disc 6 rear- Iwardly toward flange 7. To insure that the disc 6 moves freely past cam guide 18 without binding on the latter, the portion of cam guide 18 facing the sewing machine is designed as a chisel-shaped wedge 20, thereby accurately guiding the notch 17 into accurate registry with the cam guide 18.

At the same time that the forward movement of the disc 6 takes place, the feeding unit 22 moves toward winding bar 12a, which it engages resiliently, as shown in FIG. 4. At the same time, the free end of band 14 and the flat spring 23 move further, passing below the spring 13 on winding bar 12a. The feeding unit carrying spring 23, then moves back to the position indicated in FIG. 3, leaving the end of the band 14 firmly clamped to the bar 1241 by means of the spring 13. To prevent the end of band 1 4 from being withdrawn by the return movement of spring 23 on feeding unit 22, the winding bar contact surface for the band end may be provided with one or more barbs for gripping the band end.

The spring 11 on lever 9 gradually pulls the disc 6 so far toward the flange 7 that the disc is entirely disengaged from guide cam 18, and by means of the dowel 15 it again rotatably couples to flange 7. In this manner the winding unit again undergoes a rotating movement until it is stopped by cam guide 18, and the various operations are repeated in the manner described above, and continued until the desired number of bands have been produced.

The machine may be so designed that the severed endless bands may 'be gathered in bundles on the arm 1 of the sewing machine. This may be accomplished by a special device (not shown) which transfers the severed bands to the arm 1, and it may be connected to a counter which automatically turns off the sewing machine and device when the desired number of bands has been produced.

The specific manner in which the various elements are driven is independent of the principle of the present invention, as the various functions of the changing movements of the device may be controlled electromagnetically, pneumatically, mechanically or hydraulically.

It should also be noted that the outer ends of the bars 12 may be provided with band-winding-guides 25 to facilitate positioning of the band. It is also understood that any well-known coupling connection between the disc 6 and the shaft 4 may be provided. For example, a claw coupling may be employed instead of the pin or dowel 15.

It is further understood that the disc '8 may be designed to be selectively positioned axially along the shaft 4, or intermediate discs may be mounted on the shaft to facilitate production of endless bands of diflerent widths, and to insure that the sewing together of the endless band always takes place at the middle of the band loop.

What is claimed is:

1. A device for mounting upon a sewing machine having a needle and operable in conjunction with the feeding end of said machine to automatically measure a predetermined length of elastic band, form said band into an endless loop, and present the end and overlapping portion of said looped band to the sewing machine needle for the stitching of said end and portion, said device comprising a driven shaft rotatably mounted forwardly of said machine in alignment with said needle, a band winding unit carried by said shaft, and including a movable disc mounted on said shaft for rotational movement thereon and for sliding movement longitudinally therealong, said disc having a forward surface facing said sewing machine, and a plurality of bars mounted on said disc and projecting perpendicularly from the forward surface thereof, said winding unit being longitudinally slidable on said shaft between a rearward position in which said winding bars are clear of said sewing machine and a forward position in which the free end position of said winding bars are in lateral alignment with said needle, coupling means on said shaft and said disc engageable when said winding unit is in its rearward position for coupling said disc to said shaft for rotation therewith, lever means for moving said winding unit axially along said shaft between said rearward and forward positions, stop means for halting rotation of said winding unit upon completion of one revolution of the unit, said stop means comprising a guide cam fixedly mounted fonwardly of said disc when the latter is in its rearward position, and a notch in the periphery of said disc sized and positioned to receive said guide cam at the moment that said rotating disc has been moved forwardly from said rearward position by said lever means to a point where said coupling means disengages, said guide cam being of suflicient length to engage said notch during the initial sliding movement of said winding unit toward its forward position to restrain rotation of said disc, and to disengage from said notch during final movement of said winding unit to its forward position whereby said disc is freely turnable on said shaft in its forward position, a feeding unit mounted adjacent said winding unit for supplying a continuous length of band material to said winding unit such that said material is wound around said bars to form an endless loop during a single revolution of said winding unit, said feeding unit being mounted to move longitudinally along said shaft with said winding unit, and rotatively therewith when said unit is in its fonward position, and means on said shaft to stop forward movement of said winding unit at the forward position thereof wherein the end and overlapping portion of said band forming said endless loop formed on said bars are located beneath said sewing machine needle.

2. A device according to claim 1, in which a sheet spring is secured to one of the bars with its free end in tensioned engagement with said bar for insertion and retention of the end of the band from the feeding unit between said spring and said bar, allowing withdrawal of the band from the feeding unit and retention by the bars during the rotation of the disc.

3. A device according to claim 2, the feeding unit having means for moving toward the winding bar and the sheet spring, and including a second sheet spring extending beyond the feeding unit to facilitate insertion of the band end between the first sheet spring and bar.

4. A device according to claim 1, the feeding end of the sewing machine including a presser foot, a movable horizontal knife rotatably secured to the presser foot, the knife travelling behind the feeding unit and above the upper edge of the presser foot, cutting the sewn endless loops.

5. A device according to claim 1, the rearward portion of the guide cam being wedge shaped to facilitate reinsertion of the cam into said notch of said disc, compensating for any oflFset due to angular movement of the 'winding unit concurrently with the sideward sewing movements of the presser foot of the sewing machine.

6. A device according to claim 1, guides located in the endsof the bars to facilitate positioning of the band during the revolution of the winding unit.

7. A device according to claim 2, the bar with the spring secured thereto, and a second bar being positioned near the periphery of the disc with suflicient distance therebetween to allow passage of the bars on either side of the presser foot of the sewing machine when the winding unit is moved forwardly into alignment with said needle.

8. A device according to claim 7, the sewing machine including a sewing arm, and third and fourth bars positioned on the disc symmetrically disposed from the first 7 8 and second bars, the third and fourth bars being at a References Cited sufficient distance to keep the band loop clear of the arm UNITED STATES PATENTS While the winding unit is moved toward the sewing posi- 1,980,856 11/1934 Fuchs 11 2 tion.

9. A device according to claim 1, the disc having a 5 plurality of radially positioned holes for receiving a varying number of bars.

10. A device according to claim 1, the disc having at JAMES BOLER: Examiner least one groove to receive the bars.

11. A device according to claim 1, adjustable means 10 on the shaft to allow variation of the fonward axial mo've- 11263, 130 ment of the winding unit.

2,685,664 8/1954 Visconti l12l30 3,219,002 11/1965 Levy. 

